For wave plates to be employed for various optical devices in order to control the phase or the polarization of light, quartz and mica, that are birefringent crystals, and uniaxially aligned polymers (such as liquid crystals), are widely employed. For example, in a case of employing quartz or mica, being a birefringent crystal, for a quarter wave plate for transforming linearly polarized light into circularly polarized light, the quarter wave plate is produced by cutting the crystal in parallel with the crystal axis and mirror-polishing it into a thickness producing a phase difference of a quarter wavelength. In a case of uniaxially aligned polymer, a wave plate is produced by carrying out an alignment treatment by application of an electric field or an external force of e.g. a drawing operation so as to produce a desired phase difference. Generally speaking, in a case of a polymer type wave plate, due to the wavelength dispersion of the polymer, the birefringence increases as the wavelength becomes shorter, and the birefringence decreases as the wavelength becomes longer. Accordingly, such a wave plate has a birefringence opposite to an ideal birefringence for a wave plate. In order to solve this problem, Patent Document 1 proposes a technique of employing a cellulose ester film which contains a compound having at least two aromatic rings and having such a molecular structure that the conformation of the two aromatic rings has no steric hindrance. Further, Patent Documents 2 and 3 disclose a technique of adding a liquid crystal to a polymer to suppress change of birefringence due to a temperature compensation effect that is a temperature-dependent change of retardation caused by a temperature-dependent change of refractive index anisotropy of a liquid crystal cell.    Patent Document 1: JP-A-2001-91743    Patent Document 2: JP-A-8-278410    Patent Document 3: JP-A-8-190094